Process for the manufacture of products from acetyleme



; will 1:. r truce.

BERNHARD CONRAD S'IUER AND WALTER minor, or A-ACHEN, GERMANY,ASSIG1\TORS, BY ransim ASSIGNMENTS, rornncnnmrean FOUNDATION, me, ACORPORA- TIGN or DELAWARE. H

rnocnss FOR THE manurac'rmm or PRODUCTS anon ACETYLENJE.

1,421,?43. No Drawing To all whom it may concern: I Be it known that we,BERNHARD CONRAD STUER, a subject of the Netherlands, and WALTER GROB, asubject of Switzerland, and residents of Aachen, Stolberg 2, Rhineland.

Germany, have invented certain new and- -useful Improvements ina Processfor the Manufacture of Products from Acetylene, of whichthe following isa specification.

The invention relates to the manufacture of products obtained by passingacetylene, or-mixtures of acetylene with other gases, capable ofreacting with acetylene for instance ainmonia-or hydrogen sulphide, orwith vapours, for instance steam, or mixtures of acetylene with gasesandvapours, over contact subtsances at high temperatures. If the'contactsubstances used for such reactions arecatalyzers which act only by meansof surface contact, such as for instance burnt clay, pumice stone,asbestos and the like, very poor yesults are obtained. Better resultsare obtained by uslng as contact substances metal compounds, forinstance metal oxides which are capable of reduction by acetylene.

- It has been found that satisfactory results may be obtained withmetallic compounds by using them in thefo'rm of compounds containingwater of hydration, by providing that there, should be present othersubstances containing water of hydration, or by utilizing as contactsubstances simultaneously catalyzing metal compounds containing water ofhydration, and additional substances containing water of, hydration.

According to this invention, among the suitable catalyzers are metalhydrates, such as hydrated compounds of iron. These compounds give offwater during the reactions, and at the same time they are reduced by theaction of the acetylene. In place of-the hydrates, may be used hydratedoxide compounds with a smaller proportion of water, for instance, thoseobtained by slight heating of hydrates, or of other metal compounds thatcan be converted'into oxides. Gare however must be exercised in order toavoid a complete dehydration of the contact substances, such as would-beproduced by strong calcining, as-in that case they would lose theirefiiciency as well as their ability to again absorb water.

The efiiciency of the above-mentoned cata- Specification of LettersPatent.

na and of magnesia,

Patented July 4, 1922.

Application filed. November 11, 1916. Serial No. 130,928.

lyzers is enhanced by the presence of additional substances containingwater of hydration, more particularly of those which have the propertyto absorb, as well as to give off, water at higher temperatures. Suchsubstances are, for instance, hydrates of alumiand hydrated silicates.

In the presence of'such activating substances even the less efiicientcatalyzers may be successfully used. Thus for instance in themanufacture of acetaldehyde from moist acetylene the efiiciency of ironoxalate or iron carbonate and the like, or of oxides obtained therefrom,is improved by the add1t1on of hydrate of alumina, hydrate of magnesia,etc.

Among the efiicient catalyzers which are capable of reduction byacetylene, are the iron compounds, preferably the hydrates, that can beconverted into oxides.

7 found to be satisfactory contact substances.

Suitable contact substances may be manufactured in various ways. Thus,by way of example, hydrated iron precipitated from solutions of acidsalts, may be mixed with substances which in themselves are indifferentor very slightly active, such as carbonates or sulphates of alkalineearths with clay, cement and the like. In addition iron hydrate may beprecipitated together with hydrate of alumina from solutions of thesalts. Or iron hydrate is precipitated upon hydrated aluminiumormagnesium-silicates, such as fullers earth, zeoliths and the like heldin suspension in solutions of its salts.

It has been further found advantageous to submit. contact substances,more particularly such as, in addition to metal compounds capable ofreduction by acetylene, contain also hydrate-containing compounds, suchas for instance bog iron ore, and the like, before they are used, to apartial reduction under such conditions that the said monoxide and otherreducing gases, preferably at a tem erature which does not materiallyexcee 400 C. -It has also been found advantageous to carry out thepartial reduction of the contact substance with moist gases. In.carrying out-the requantities of oxygen.

actions, these partially reduced contact masses are preferably usedunder conditions which will avoid a further reduction to ,metal by theaction of acetylene, for the formation of metal favors the undesireddecomposition of the acetylene with the formation of carbon. For thisreason, 'it is advisable to avoid the use of excessively hightemperatures. The partially reduced contact substances posess theadvantage that the formation of the more valuable reaction products oflower boiling point is favorably influenced and, whilst the formation ofreaction products with a higher boiling point is retarded. Whenacetylene, or acetylene diluted with neutral gases, is passed overpartially reduced bog-iron ore, or the like, less acetylene will bedecomposed with formation of carbon, than when non reduced, orcompletely reduced, contactsubstances are used. The oxidation ofacetylene to carbon monoxide and carbon dioxide, always accompanying themanufacture of products from acetylene, which is liable to lead todifficulties for instance during the reaction between acetylene andammonia owing to the formation of ammonium carbonate and ammoniumcarbamate, is prevented, or at least strongliy retarded, by the use ofthe partly re uced contact substances.

The presence of substances yielding oxygen, such as chromic acid,chromates, nitrates, and the like, in the contact substance has beenfound to be advantageous. Instead of using substances ielding oxy en,the process may be carried to the reaction gases small quantities ofoxygen, or substances giving off oxygen may be used simultaneously withsmall Working. in the presence of substances giving off oxygen, or withthe addition of oxygen, chiefly favors oxidation reactions, for instancethe formation of acetaldehyde and acetic acid, by passing a mixture ofacetylene and steam over contact substances. If mixtures of acetyleneand oxygen are treated so as to obtain acetaldehyde and acetic acid, itis ":lvisable to use a large excess of acetylene and to avoidexcesivelyhigh temperatures, for instance those above 380 0., as otherwise largequantities of acetylene will be lostin out by ad ing.

dioxide.

But even in pure synthetic reactions, for instance in the reaction ofacetylene with ammonia, or hydrogen sulphide, the presence of smallquantities of oxygen or'of substances giving off oxygen, or of both, is

an advantage, as their presence retards the formation of high molecularroducts, and

thus favors the formation oft e more valuable simpler products.

Finally, the presence in the contact substance of such substances, ascompounds of the alkalis, alkaline earths, and magnesium, which forexample, have the property of assisting the re-oxidation of iron oxidereduced by the action of acetylene, has also proved advantageous.

. The contact substances of this invention are suitable for themanufacture of oxygencontaining products obtained from acetylene andsteam, as well as of nitrogen-containing products obtained fromacetylene and ammonia and of sulphur-containing products obtained fromacetylene and hydrogen sulphide or from other sulphur-containing gases.When mixtures of these gases or vapours, for instance acetylene, steamand ammonia, are used, products are formed which, like aldehyde ammonia,contain both oxygen and nitrogen. When acetylene and steam are used,synthetic products as well as products of oxidation, are formed. Thepresence of a little steam assists the formation of synthetic products,whilst a large quantity of steam and high temperatures assist theformation of oxidation, products such as for instance acetaldehyde andacetic' the form of carbon monoxide and carbon.

At temperatures above 500 (3., the formation of carbon dioxide generallybecomes very prominent. The synthetic and oxidation reactions accordingto this invention may be carried out at an ordinary, as well as at anincreased, pressure.

' When such processes are carried out, more particularly those whichtake place in the absence of steam, or in the presence of-a littlesteam, substances are formed which volatilize with difliculty, and whichcover the surface of the contact substance and affect its .action. Thisdisadvantage may be materially avoided by the use of partially reducedcontact material.

4 Furthermore, in accordance with the invention, contact material whichhas lost its activity, may be regenerated by passing over it, at a hightemperature, oxygen or emme oxygen-containing gases, such as air,preferably moist, and in that way oxidizing the high molecular carboncompounds and other impurities. In certain cases, it is advisable to usea subsequent treatment of the contact material with steam orwater forthe purpose of hydrating the compounds partly dehydrated during thetreatment with oxygen.

- stance, compact. metals, such as nickel in the form of bands ,orwires, might be used as a contact material. Durin the passage ofacetylene substances are t en produced similar tocoal or containing highmolecular carbon compounds, the said substances containing the metalused, such as nickel, copper, iron, in a state of fine division andconstituting contact substances having an excellent action. Thus in themanufacture of sulphur-containing synthetic products, it is possible tostart successfully with a contact substance which, in the course of theprocess is completely or partly reduced to metal, or with a contactsubstance, the metal compound of which has been entirely or part1"converted, before the process, into the orm of metal by an extensivereduction. A very efiic'ient contact substance con- 'taining metallicnickel for the manufacture of sul bur-containing products may, for exame, be obtained by mixing hydrated nicke -oxide with cement, and treatingthe vessel are condensed, and the portion which does not condense, isdeprived of the volatile reaction products by washing with water,glacial acetic acid or other absorbent, if desired, with cooling, andthen they may again be passed over the contact substance. Acetaldehydewill be obtained as the chief product of the reaction. In addition therewill appear small quantities of productsof higher molecular weight suchas acetone aldehyde. A portion of the acetaldehyde will have beenoxidized further to acetic acid.

If the passage is effected only once, 15-16% of acetylene is convertedinto acetaldehyde. The temperature of the reaction is generally between300600 C., but even at higher temperatures, considerable quantities ofacetaldehyde are obtained.

E mample 2.-Acetylene charged with a small amount of steam by passing itthrough water at a suitable temperature, is passed over bog iron orewhich has been first partly reduced by passing hydrogen over it at 350 CThe reaction gases are condensed by cooling to about 7 0-80, thenfurther cooled for the purpose of obtaining the more volatileingredients, and finally washed with water or other solvent foracetaldehyde, which may be cooled. The condensate is a yellowishgreen tobrown oil which is lighter than water, and when water in excess is used,it will separate as a well-defined upper layer. The condensate containshigher aldehydes, acetone, alcohol, acetic acid and homologues,furfurane derivitives, phenols, creosote-like products and, in additionhydrocarbons, resinand tar-like substances. The condensate insoluble inwater may be separated into its constituents by fractional distillation,and has valuable technical properties; thus, for instance, it is a goodsolvent for resins.

Example 3.Acetylene and ammonia are passed at about 350380 C., overbauxite. The escaping gases are condensed, and subsequently Washed, ifdesired with cooling, with water, Xylol or other means of absorption.Unconsumed ammonia is recovered from the residual gases by washing withWater or by condensation and is again brought into the reaction. Thereaction products will comprise nitriles and nitrogencontaining bases,more particularly acet-onitrile will'be formed to the extent of 50% ofthe acetylene used, in addition-'picoline and its homologous pyridinebases together with the pyrroles and other nitrogen-com tainingproducts.

The special action of the hydrated contact substances, or ofproductspoorer in water obtained from them by slight heating, becomesparticularly noticeable in the reaction of ammonia on acetylene, forwhen the present contact substances are used, only such substances areobtained ascontain the two carbon atoms of the acetylene bond, whilst,for instance, when metal contact substances are used, or metal oxides,[under conditions in which they are reduced to metals, cyanide ofhydrogen or cyanide of ammonium is obtained, that is to say productswhich are formed by splitting the carbon bond of the acetylene.

E mample 4.Acetylene and hydrogen sulphide, for instance in theproportion of 2 to 1, are passed at 300 C'. over contact sub.

stances produced mixing nickel hydroxide with cement, and subsequentlydrying at 1 300 C. The escaping gases are condensed is a cleartransparent liquid upon repeated distillation, .it ,distils almostentirel below 120. It is therefore a practically pure thiophene.\Products of higher molecular wei ht are formed only in smallquantities.

- hat we claimisz- 1. A process for the manufacture of products fromacetylene which comprises passing acetylene in conjunctionwith anotherreaction gas over a hydratedmetal compound at a tem' rature of 250 to500 C.

2. process for the manufacture of products from acetylene whichcomprises passing acetylene in. conjunction with another reaction gasover a hydrated metal oxide at a temperature of 250 to 500 C.

3. A process for the manufacture of products from acetylene whichcomprises passing acetylene in conjunction with another reaction gasover a hydrated iron oxide at a temperature of 250 to 500 C.

4. A process for the manufacture of products from acetylene whichcomprises passing acetylene in conjunction with another reaction gasover bo iron cm at a temperature of 250 to 500 5; A catalyst foreffecting reactions with acetylene containing an iron compound andhydrated alumina.

6. A catalyst for effecting reactions with acetylene containing ametallic compound and an oxygen yielding compound.

he process of'producing catalysts for effecting reactions with acetylenewhich com- 'mixture of various sulphur compounds from whlch mercaptan,

' \i i prises partially dehydratin and partially reducing hydrated ironoxi e. i

' 8. The process o-f'producing catalysts for effecting reactions withacetylene which comprises partially dehydrating and partially reducingbog iron ore.

9. The process of producing catalysts for I effecting reactions withacetylene which comprises passing a reducingegas over a hydratecontaining iron compbuhd at approximately 400 C'. and terminating thereaction before .metal is formed.

, 10." The process of producing catalysts for effecting react-ions withacetylene which comprises passing hydrogen containing gas over ahydrated iron oxide at approximately 400 (3. and terminating thereaction before metal is formed. o

11. The process of producing catalysts for effecting reactions withacetylene which com prises passing a moist reducing gas over a lydratediron oxide at approxlmately 400 and terminating the reaction beforemetal is formed.

12. A process for the manufacture of products from acetylene whichcomprises passing acetylene and hydrogen sulphide over a hydra-ted metalcompound at a-temperature of from about 250 to 500 C.

13. A process for the manufacture of products from acetylene whichcomprises passing acetylene and hydrogen sulphide over a reduced,butfree from metal, hydrated metal compound at a temperature of from about250 to 500 C.

14. A process for the manufacture of products from acetylene whichcomprises passing acetylene and hydrogen sulphide over a reduced, butfree from metal, hydrated metal oxide at a temperature of from about 250to 500 C.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing witnesses.

DR. BERNHARD CONRAD STUER. DR. WALTER GROB.

" Witnesses: HENRY C. A. DAMM,

HENRY ANADFLIEG.

